NAME¶
HTTP::Proxy::BodyFilter::htmlparser - Filter using HTML::Parser
SYNOPSIS¶
use HTTP::Proxy::BodyFilter::htmlparser;
# $parser is a HTML::Parser object
$proxy->push_filter(
mime => 'text/html',
response => HTTP::Proxy::BodyFilter::htmlparser->new( $parser );
);
DESCRIPTION¶
The HTTP::Proxy::BodyFilter::htmlparser lets you create a filter based on the
HTML::Parser object of your choice.
This filter takes a HTML::Parser object as an argument to its constructor. The
filter is either read-only or read-write. A read-only filter will not allow
you to change the data on the fly. If you request a read-write filter, you'll
have to rewrite the response-body completely.
With a read-write filter, you
must recreate the whole body data. This is
mainly due to the fact that the HTML::Parser has its own buffering system, and
that there is no easy way to correlate the data that triggered the
HTML::Parser event and its original position in the chunk sent by the origin
server. See below for details.
Note that a simple filter that modify the HTML text (not the tags) can be
created more easily with HTTP::Proxy::BodyFilter::htmltext.
Creating a HTML::Parser that rewrites pages¶
A read-write filter is declared by passing "rw => 1" to the
constructor:
HTTP::Proxy::BodyFilter::htmlparser->new( $parser, rw => 1 );
To be able to modify the body of a message, a filter created with
HTTP::Proxy::BodyFilter::htmlparser must rewrite it completely. The
HTML::Parser object can update a special attribute named "output".
To do so, the HTML::Parser handler will have to request the "self"
attribute (that is to say, require access to the parser itself) and update its
"output" key.
The following attributes are added to the HTML::Parser object by this filter:
- output
- A string that will hold the data sent back by the proxy.
This string will be used as a replacement for the body data only if the
filter is read-write, that is to say, if it was initialised with "rw
=> 1".
Data should always be appended to
"$parser->{output}".
- message
- A reference to the HTTP::Message that triggered the filter.
- protocol
- A reference to the HTTP::Protocol object.
METHODS¶
This filter defines three methods, called automatically:
- filter()
- The "filter()" method handles all the interactions with the
HTML::Parser object.
- init()
- Initialise the filter with the HTML::Parser object passed to the
constructor.
- will_modify()
- This method returns a boolean value that indicates to the system if it
will modify the data passing through. The value is actually the value of
the "rw" parameter passed to the constructor.
SEE ALSO¶
HTTP::Proxy, HTTP::Proxy::Bodyfilter, HTTP::Proxy::BodyFilter::htmltext.
AUTHOR¶
Philippe "BooK" Bruhat, <book@cpan.org>.
COPYRIGHT¶
Copyright 2003-2013, Philippe Bruhat.
LICENSE¶
This module is free software; you can redistribute it or modify it under the
same terms as Perl itself.